From b0697eccbea9adec5b7ba8008f4c33d98d733388 Mon Sep 17 00:00:00 2001
From: Andreas Auernhammer <aead@mail.de>
Date: Mon, 23 Apr 2018 15:30:03 +0200
Subject: [PATCH] blake2b: Revert "blake2b: use internal/cpu to determine AVX
 and SSE 4 support"

This reverts commit d6449816ce06963d9d136eee5a56fca5b0616e7e because of golang/go#24828.

Change-Id: I14b4e1265b2e75897fa12548dbdfb77c308afaaf
Reviewed-on: https://go-review.googlesource.com/108795
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
---
 blake2b/blake2bAVX2_amd64.go | 26 ++++++++++++--------------
 blake2b/blake2bAVX2_amd64.s  | 12 ++++++++++++
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/blake2b/blake2bAVX2_amd64.go b/blake2b/blake2bAVX2_amd64.go
index a1e08d7..8c41cf6 100644
--- a/blake2b/blake2bAVX2_amd64.go
+++ b/blake2b/blake2bAVX2_amd64.go
@@ -6,23 +6,21 @@
 
 package blake2b
 
-import _ "unsafe"
-
-//go:linkname x86_HasAVX internal/cpu.X86.HasAVX
-var x86_HasAVX bool
-
-//go:linkname x86_HasAVX2 internal/cpu.X86.HasAVX2
-var x86_HasAVX2 bool
-
-//go:linkname x86_HasAVX internal/cpu.X86.HasSSE4
-var x86_HasSSE4 bool
-
 func init() {
-	useAVX2 = x86_HasAVX2
-	useAVX = x86_HasAVX
-	useSSE4 = x86_HasSSE4
+	useAVX2 = supportsAVX2()
+	useAVX = supportsAVX()
+	useSSE4 = supportsSSE4()
 }
 
+//go:noescape
+func supportsSSE4() bool
+
+//go:noescape
+func supportsAVX() bool
+
+//go:noescape
+func supportsAVX2() bool
+
 //go:noescape
 func hashBlocksAVX2(h *[8]uint64, c *[2]uint64, flag uint64, blocks []byte)
 
diff --git a/blake2b/blake2bAVX2_amd64.s b/blake2b/blake2bAVX2_amd64.s
index 5593b1b..784bce6 100644
--- a/blake2b/blake2bAVX2_amd64.s
+++ b/blake2b/blake2bAVX2_amd64.s
@@ -748,3 +748,15 @@ noinc:
 
 	MOVQ BP, SP
 	RET
+
+// func supportsAVX2() bool
+TEXT ·supportsAVX2(SB), 4, $0-1
+	MOVQ runtime·support_avx2(SB), AX
+	MOVB AX, ret+0(FP)
+	RET
+
+// func supportsAVX() bool
+TEXT ·supportsAVX(SB), 4, $0-1
+	MOVQ runtime·support_avx(SB), AX
+	MOVB AX, ret+0(FP)
+	RET